KA2: Control and Communication Flashcards
What is the nervous system made up of
The Central Nervous System and other nerves
What is the Central Nervous System made up of
The brain and spinal cord
What is the brain made up of
Billions of neurones
What is a neuron
Nerve cell
What is the cerebrum
The largest part of the brain, split into 2 halves. Controls memory, personality, creativity and thoughts
What is the cerebellum
Controls balance and co-ordination
What is the medulla
Controls some vital body functions like heart rate and breathing rate
What is a nerve cell also known as
Neuron
What are the 3 types of neurons and what do they do
Sensory - pass sensory information to the CNS
Inter - Operates in the CNS
Motor - Enables a response to occur at an effector (muscle or gland)
What is a synapse
A gap between 2 neurons
How do chemicals transfer messages
By diffusing across a synapse
What are the stages of synapse
- Electrical impulse reached end of one neuron where there are tiny vacuoles containing chemicals
- Chemicals transfer message across synapse
- Receptors on the neuron capture the chemicals
- The electrical impulse continues along the neuron
Whats the difference between electrical impulses and chemical messages
Electrical impulses travel along a neuron
Chemical messaged pass across neurons at the synapse
What are reflexes
Rapid, automatic and protective actions in response to damaging stimuli
What is an example of reflexes
Withdrawal from extreme heat and pain
Blinking to clear eye
Coughing to clear windpipe
Sneezing to clear air passages
What are the stages of reflex arc
A stimulus occurs
Detected by receptors in the skin
Impulses travel along sensory neurons
Passed along the inter neuron
Impulses travel along motor neurons
Effector is a muscle
Response
What are hormones?
Hormones are chemical messengers found in the endocrine system
What do endocrine glands release?
Hormones into the bloodstream to target organs
What do target organs have?
Cells with complementary receptor proteins for specific hormones
What are the hormones? (6)
Testosterone
Progesterone
Insulin
Thyroxin
ADH
Adrenaline
What monitors glucose concentration?
Glucose receptors in the pancreas
What does the liver do?
Acts as a resevoir for carbohydrate and stores extra glucose as the insoluable carbohydrate glycogen
What hormones are involved in the regulation of blood glucose concentration?
Insulin
Glucagon
What would cause blood glucose to increase?
Eating increases blood glucose
The rise is detected by receptors in the pancreas
Pancreas produces insulin
Insulin travels in the blod to the liver
This stimulates the liver to store it as glycogen to decrease the blood glucose concentration
Blood glucose concentration returned to normal
What would cause blood glucose to decrease?
Missing a meal or exercise decreases
The fall is detected by receptors in the pancreas
Pancreas produces glucagon
Glucagon travels to liver
This stimulates it to convert glycogen to glucose increasing the blood glucose concentration
Blood glucose concentration returned to normal
